4. A mover wants to push a box down a hall. The mover applies an ‘action’ force on the box (the push). According to Newton’s 3rd law, there is a ‘reaction’ force applied in the opposite direction. The larger the action force applied by the mover, the larger the reaction force will be. How is it possible, then, for the box to move (be accelerated)?

According to Newton's third law of motion, for every action, there is an equal and opposite reaction. In the case of the mover pushing a box down a hall, the mover applies an action force on the box, causing a reaction force in the opposite direction.

However, it's important to note that these two forces are acting on different objects. The action force is applied on the box by the mover, and the reaction force is applied on the mover by the box. The force applied on the mover does not directly affect the motion of the box.

What allows the box to move is not the reaction force on the mover, but rather the net force acting on the box itself. The net force is the vector sum of all the forces acting on an object. In this case, the box experiences two forces - the force applied by the mover and any other external forces such as friction.

If the action force applied by the mover is larger than the opposing forces (like friction), there will be a net force acting on the box. According to Newton's second law of motion (F = ma), this net force will cause the box to accelerate in the direction of the force. Acceleration is the result of an imbalance of forces acting on an object.

So, even though there is an equal and opposite reaction force on the mover, it does not prevent the box from moving. The box's motion is determined by the net force acting on it, which is the difference between the forces applied and the opposing forces like friction.